I pull a large caravan with my 2006 Ford Galaxy 1.9 TDI 115ps, within towing regulations. In France on a long hill, not overly steep, there was a big drop in power - it felt like the turbo dropped out. I stopped for 10 minutes, switched off the air conditioning and there was no more issue. On returning home, the same happened again and I could not get above fourth gear. After the ferry journey, all was ok again. The engine felt surprisingly cool. Again, it felt as if turbo dropped out. Is this a problem you have heard of?